The Fourth Republican Guard was formed in March or April 3029 as the Fourth Republican BattleMech Regiment, part of the Tikonov Free Republic Army.[1] Following negotiations between ColonelPavel Ridzik, (former) chief military advisor to ChancellorMaximillian Liao of the Capellan Confederation, and AFFSLieutenant GeneralArdan Sortek, conducted in February 3029, Ridzik created his own breakaway nation, the Tikonov Free Republic. The Republic was created by incorporating those worlds of the Capellan Tikonov Commonality that hadn't already been conquered during the first half of the Fourth Succession War. Ridzik returned to Elgin, the new capital of the Tikonov Free Republic, on the 3rd of March 3029 and swiftly began implementing a new government consisting of family members, friends and other appointees loyal to himself, purging dissident elements on the various Republic worlds and taking the opportunity to settle old scores. He also formed the Tikonov Free Republic Army, purging those military forces available to him in an effort to ensure the troops were loyal to him.[2] The Fourth was one of five 'Mech regiments established at the founding of the TFRA, and like one of it sister regiments, the Fifth Republican BattleMech Regiment, the Fifth was created by taking individual soldiers formerly of the Capellan Confederation Armed Forces who had survived the Fourth Succession War to date and combining them with new graduates of MechWarrior training programs.[1]

Goaded by requests from ArchonKatrina Steiner and First PrinceHanse Davion, and aided by advice from Ardan Sortek, Pavel Ridzik decided to launch an offensive against the Free Worlds League in the second quarter of 3029. Ridzik's offensive targeted four League worlds, one of which was Talitha. Talitha was expected to be an easy campaign, as the planet was defended solely by a planetary militia. The Fourth was assigned to conquering Talitha, supported by an armor regiment and two regiments of infantry. The TFRA forces quickly routed the planetary militia and captured the planet.[1]

Following the assassination of Lord Ridzik by an agent of the House Liao's Maskirovka and the sussequent absorption of his Free Tikonov Republic into the Federated Commonwealth, the Fourth Republican along with its sister regiments joined the AFFC (though rated at "questionable" loyalty), and as of January 3050 were part of the FedCom's Nanking Command together with the Nanking SMM, the 2nd FedCom RCT and Wolf's Dragoons (with only the latter two units considered reliably loyal to the FedCom).[3]

As with the other regiments of the Tikonov Republican Guards, the Fourth's first true test came during Operation Guerrero, the Marik-Liao Invasion of 3057. Garrisoned on Hall since the conclusion of the Fourth Succession War the Fourth was a hotbed of anti-FedCom sentiment with a reputation for discipline problems and unreliability despite the unit's short history of existence. Upon hearing of the Marik-Liao attack, the Fourth prepared to resist the impending invasion that ultimately never came. Rather than send troops, Chancellor Sun-Tzu Liao had his agents foment rebellion on Hall which was ruthlessly crushed by the Fourth Republican Guards. In the chaos following the secession of Katrina Steiner-Davion and the Lyran Alliance from the Federated Commonwealth, thus leaving the entirety of the Sarna March exposed and vulnerable the Fourth Republican's commander the opportunistic Leftenant General William "Bud" Baranov saw the writing on the wall and went rogue with his unit in tow, proceeding to seize Hall for themselves.[4]

After a quick meeting with his officers, Baranov led the Fourth to Hall's planetary capital city of Harney, swatting aside the local opposition and declaring himself Emperor of Hall. Upon seizing the capital, Baranov and the Fourth were largely unopposed by the planet's populace. Soon after, however, two rival factions arose, one led by Count Radliffe McNally - a local planetary noble with sufficient military strength and economic assets to resist Baranov, and the other being Cater's Cohorts, led by Major Dick Cater and consisting of former Fourth Republican personnel who had turned against Baranov shortly after he seized Harney. Also on Hall were the twin sons of Baranov's former master Pavel Ridzik, Yuri and Nikoli Ridzik, who had recruited a small army and brought their force to Hall hidden from the eyes of Baranov and the Fourth hoping to eliminate Baranov and resurrect their father's Tikonov Free Republic.[5]

After Major Cater's rebellious troops were forced to withdraw to Hall's southern hemisphere, the three major factions on Hall settled into their respective territories, occasionally fighting each other for supplies and territory. In the mean time, Baranov and the Fourth turned towards the Ridzik Twins in which Baranov skillfully manipulated the situation, causing the disappearance of Nikoli and sending his brother fleeing off planet, thus eliminating the threat the Twins posed with their small military force.[6] Next, Baranov and the Fourth turned again to Major Cater and his rebellious troops, eventually engaging and shattering Cater's Cohorts and allowing Baranov and the Fourth to further consolidate their control of Hall.

Soon Count McNally and his array of forces were the only obstacle preventing Baranov from controlling the planet. Hall gradually settled into a stand-off between the Baranov's Republican Guards and Count McNally's coalition of forces including his own McNally Guard, Burton's Brigade, the remnants of Cater's Cohorts, and the mercenary Critchley's Cavaliers.

The stand-off between Baranov and McNally was finally broken in late 3066 when the Fourth Republican Guards, supported by the mercenary Stealthy Tigers, finally overwhelmed the forces of Count McNally, killing the Count and routing his surviving forces, earning Baranov tenuous control over Hall. The survivors of Count McNally's forces, led by Burton's Brigade (Elly Burton being the mother of McNally's child) allied themselves with the Com Guard troops hoping to escape Baranov's wrath, and entrenched themselves.

Following the formation of the Allied Mercenary Command to combat the spread of Word of Blake influence in what was now the Chaos March, the 3rd Dismal Disinherited regiment was sent to Hall by the AMC to support the Com Guard troops already on planet to ward off against Blakist operations and investigate suspected ties between Baranov and the Word of Blake. Then in the summer of 3067, Emperor Baranov announced that he had invited the Free Worlds League to annex Hall, hence undermining the positions of both the Com Guard and the AMC troops on planet and legally forcing all those forces aligned against him to withdraw off world.

Combat again broke out when the Colonel John Marik-Johns of the 3rd Dismal Disinherited refused to recognize the authority of the 4th Oriente Hussars which had arrived on Hall to officially annex the planet on behalf of the Free Worlds League. Convinced the whole thing was a Blakist ploy, Colonel Marik-Johns commanded his 3rd Dismal Disinherited and Burton's Brigade to attack the 4th Oriente Hussars who were in turn supported by Emperor Baranov's troops including the Fourth Republican Guards and the Stealthy Tigers. The renewed fighting on Hall was short but fierce, lasting less than a month and ending ultimately with a League victory but not before Emperor Baranov and Captain Elly Burton had perished in a 'Mech duel during the final confrontation in Harney.[7] This coincided with the Fourth Whitting Conference and the outbreak of the Jihad.